The ground shook and people had to cover their ears as replica fieldguns were fired at a military re-enactment of the Battle of Gate Pa on Saturday at the Tauranga Domain.
More than 100 spectators attended the 150 years' commemorations, with replicas of the same guns used in the 1864 battle being fired again.
Three blasts from two six-pounder Armstrong fieldguns and five 12-pounder Coehorn mortars were fired throughout the day, from 10am to 2pm.
The replicas were built for the New Zealand-made film Utu Redux and one of the fieldguns and one mortar were now displayed in the ANZ Bank in Greerton.
NZ Armed Constabulary Re-enactment Unit commandant John Osborne said the Armstrong guns were brought to the battlefield on April 28, 1864, and set up in a battery with Coehorn mortars at a range of 350 yards (320 metres). The six-pounder guns supported an all-day artillery barrage of the pa site, lasting most of April 29.
Two six-pounder guns were dragged across Kopurererua swamp and set up on the hillside opposite the pa, to fire directly into it.
Believing the artillery barrage had killed all the Maori warriors, the 43rd Regiment of sailors, marines and soldiers charged, but the Maori defenders were mostly unharmed as they had sheltered in deep trenches and bunkers.
"The attacking soldiers and sailors were met by a withering fire from the hidden defenders, with many of them killed or wounded. The survivors turned and fled," Mr Osborne said. People could inspect the guns and got a chance to fire them by entering a free raffle.
Ten-year-old Jack Hoggard said he was excited to fire a Coehorn mortar when his ticket number was drawn.
"It was really cool" he said.
He was looking forward to going back to school to tell his Bethlehem Primary School classmates about the experience.
Kyle Burden, 8, also had the chance to fire a mortar.
"It burned your cheek when you shot it," he said.
Saturday's events were the first of many building up to the biggest day of commemorative events, on April 29.